• Journal of Applied Biological Chemistry
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• 제55권1호
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• pp.27-34
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• 2012

Soy protein isolate (SPI)-based edible coating, with and without carboxymethyl cellulose (CMC), were used to reduce oxidative degradation of cut pork stored at $4^{\circ}C$ for 5 days. The SPI coating reduced (p<0.05) thiobarbituric acid-reactive substances (TBARS) and peroxide value (PV), compared with controls. The inhibition of TBARS and PV for SPI-coated porks with and without CMC, compared with the control was 19.1 and 23.9, and 25.7 and 37.7%, respectively. The SPI coating prevented loss of $L^*$ and $a^*$ values of porks compared to the control. The ability of the SPI coating to provide a moisture barrier for the porks was reduced (p<0.05). The SPI-coated porks with and without CMC reduced moisture loss by 37.3 and 44.6%, respectively, over the control. However, SPI coating of porks did not inhibit the growth of either total plate counts or L. monocytogenes. The result revealed that SPI can effectively be used as a natural antioxidative coating to extend quality and shelf life of pork.

• 대한수의학회지
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• 제49권1호
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• pp.59-62
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• 2009

Susceptibility to chronic wasting disease (CWD) in cervid species has been associated with polymorphisms in the prion protein gene (PRNP). The single nucleotide polymorphisms (SNPs) were found in the PRNP of the Korean subspecies of Chinese water deer via analyses of the DNA sequences obtained from 34 individual deer. Two SNPs were detected at codons 77 and 100. One SNP at codon 77 encoding Glycine was determined to be a silent mutation but the other SNP detected at codon 100 induced an amino acid change, from Asparagine to Serine. The prion protein (PrP) amino acid sequence of the water deer showed 98.8-99.2% homology with those of American elk, white-tailed deer and mule deer. The PrP of the water deer contained amino acid residues closely related with CWD-susceptibility. This study is the first to describe genetic variations in the PRNP of the Korean subspecies of Chinese water deer.

• BMB Reports
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• 제34권6호
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• pp.573-577
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• 2001

The mammalian heart is known to undergo significant mechanical changes during fetal and neonatal development. The objective of this study was to define the ontogeny of the ryanodine receptor/$Ca^{2+}$ release channel and SERCA that play the major roles in excitation-contraction coupling. Whole ventricular homogenates of fetal (F) (19 and 22 days in gestation), postnatal (N) (1 and 7 days postnatal), and adult (A) (5 weeks postnatal) Sprague-Dawley rat hearts were used to study [$^3H$]ryanodine binding and oxalate-supported $^{45}Ca^{2+}$ uptake. For the ryanodine receptor, the major findings were: (1) The ryanodine receptor density, as determined by maximal [$^3H$]ryanodine binding ($B_{max}$), increased 3 fold between the F22 and A periods ($0.26{\pm}0.1$ vs. $0.73{\pm}0.07$ pmoles/mg protein, p<0.01), whereas there was no significant change during the F22 and N1 development phases ($0.26{\pm}0.1$ vs. $0.34{\pm}0.01$). (2) Affinity of the ryanodine receptor to ryanodine did not significantly change, as suggested by the lack of change in the $K_d$ during the development and maturation. For SERCA, changes started early with an increased rate of $Ca^{2+}$ uptake in the fetal periods (F19: $8.1{\pm}1.1$ vs. F22: $19.3{\pm}2.2$ nmoles/g protein/min; p<0.05) and peaked by 7 days (N7) of the postnatal age ($34.9{\pm}2.1$). Thus, we conclude that the quantitative changes occur in the ryanodine receptor during myocardial development. Also, the maturation of the $Ca^{2+}$ uptake appears to start earlier than that of the $Ca^{2+}$ release.

• 한국미생물·생명공학회지
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• 제34권3호
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• pp.211-215
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• 2006

S. lividans에서 클로닝된 조절유전자인 afsR2를 과발현시 나타나는 up-regulated protein과 down-regulated protein 관련 유전자들을 proteomics 방법으로 선별하였고[3], 이를 방선균 발현벡터인 pSE34를 이용하여 제작된 pPNP, pGPD를 S. avermitilis에 형질전환시켜 avermectin 및 이차대사산물의 생산량 차이를 비교 분석하였다. 그 결과 up-regulated protein으로 예상되던 PNP는 wild-type S. avermitilis에서만 제한적으로 avermetin-type 대사산물의 생산성 향상을 촉진시켰으며, 이와 반대로 down-regulated protein으로 예상되었던 GPD는 avermectin-type 대사산물의 생산량을 wild type S. avermitilis에서는 4배, over-producer S. avermitilis에서는 2.5배 증가시켰다. 본 연구결과는, 방선균 조절 단백질들이 이차대사산물의 종류 및 생합성 기작에 따라 전혀 다르게 작용될 수 있음을 암시하며, 향후 이들 조절 단백질들에 대한 보다 구체적인 분자수준에서의 연구 필요성을 제시하고 있다.

• 한국식품저장유통학회지
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• 제22권3호
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• pp.361-368
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• 2015

본 연구에서는 약주 이취 원인물질을 알아보기 위해 단백질과 쌀지방을 첨가하여 약주를 제조하고 확인하였다. 알코올 함량은 쌀약주의 대조구가 14.5%, 단백질 첨가구 14.2%, 지방 첨가구 13.4%로 지방첨가에 의해서 알코올 농도가 낮아졌다. 포도당 약주에도 지방 첨가에 의해서 알코올 농도가 25.2% 감소하였다. 총산(succinic acid, %)은 단백질 첨가에 의해서 쌀약주가 0.33에서 0.48%로 포도당약주는 0.34에서 0.57% 증가하였고 총 아미노산 함량도 각각 0.67, 0.15%(as glycine)에서 1.48 및 1.29%로 증가하였다. 유기산은 succinic acid와 citric acid의 함량이 가장 높게 나타났다. 유리 질소화합물의 함량은 단백질 첨가에 의해서 각각 4,377.38, 699.35 ppm에서 10,208.06과 9,368.93 ppm으로 상승하였다. 주요 유리 질소화합물 성분으로는 arginine, glutamic acid, leucine, alanine이 총량의 8.17~10.40%의 범위로 가장 높게 나타났다. 단백질은 이취에 대하여 0.98(p<0.001)의 높은 상관계수를 보였고 지방은 -.038(p<0.458)로 음의 상관성을 나타내었다.

• BMB Reports
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• 제34권6호
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• pp.537-543
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• 2001

In the present study, an in vitro ELISA system to assess the interaction between Src homology (SH)2 domains and phosphotyrosine that contain peptides was established using purified GST-conjugated SH2 proteins and synthetic biotinylated phosphotyrosine that contain oligopeptides. The SH2 domains bound the relevant phosphopeptides that were immobilized in the streptavidin-coated microtiter plate in a highly specific and dose-dependent manner. The epidermal growth factor receptor (EGFR)-, T antigen (T Ag)-, and platelet-derived growth factor receptor (PDGFR)-derived phosphopeptides interacted with the growth factor receptor binding protein (Grb)2/SH2, Lck/SH2, and phosphatidyl inositol 3-kinase (PI3K) p85/SH2, respectively. No cross-reactions were observed. Competitive inhibition experiments showed that a short phosphopeptide of only four amino acids was long enough to determine the binding specificity. Optimal concentrations of the GST-SH2 fusion protein and phosphopeptide in this new ELISA system for screening the binding blockers were chosen at 2nM and 500nM, respectively. When two candidate compounds were tested in our ELISA system, they specifically inhibited the Lck/SH2 and/or p85/SH2 binding to the relevant phosphopeptides. Our results indicate that this ELISA system could be used as an easy screening method for the discovery of specific binding blockers of protein-protein interactions via SH2 domains.

• Journal of Nutrition and Health
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• 제24권2호
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• pp.124-131
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• 1991

식이 단백질 섭취수준 및 동·식물성 단백질 급원이 칼슘 및 인대사에 미치는 영향을 검토하기 위하여 10명의 한국성인 연성을 대상으로 26일간의 통제 식이실험을 실시하였다. 대사실험 연구는 6일간의 적응기간과 10일간의 중단백식이(60g 단백질 545mg Ca)와 10일간의 고단백질 식이(90g 단백질 575mg Ca)로 구성되었다 중·고단백 식이기간 동안 동물성 단백질(75% 동물성 단백질)과 식물성 단백질(75% 식물성 단백질) 식이군으로 나누어 같은 식이에서 중단백식이 후 고단백식이를 섭취토록 하였고 실험식이 마지막 4일간은 각 2명에게 300mg 칼슘을 보충시켰다. 칼슘 흡수율은 단백질 섭취량의 증가시 동물성 단백질 식이군에서 유의적으로 증가하였다, 칼슘 보충은 급원에 관계없이 칼슘 흡수를 증가시켰다. 중단백 식이기간 동안 동물성과 단백질 식이에서 칼슘흡수율은 약 30% 이었으며 고단백질식이 기간 동안 동물성 단백질에서 46% 식물성 단백질에서 37% 이었다. 칼슘을 보충시켰을 때 중단백 식이기간동안 칼슘 흡수율은 약 46% 이었으며 고단백 식이군에서 53%이었다 뇨중 칼슘배설은 단백질 섭취수준에는 영향을 받지 않았으나 동물성 단백질 식이에서 식물성 단백질 식이보다 칼슘배설양이 많았다. 칼슘 균형을 단백질 섭취증가와 칼슘 보충으로 호전되었다. 인의 흡수는 단백질 섭취수준에는 영향을 받지않았으며 인 섭취량에 따라 증가하였다. 인 흡수율은 동물성 단백질 식이군에서 약 77∼81% 로 식물성 단백질 식이군에서의 55∼65% 보다 높았다. 이상의 결과로 보아 단백질 섭취수준 60g에서 90g으로의 증가와 칼슘보충은 뇨중 칼슘 배설에는 영향을 주지않으며 칼슘 흡수를 증진시켜 칼슘균형을 호전시키는 것으로 나타났다.

• Fisheries and Aquatic Sciences
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• 제23권1호
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• pp.1.1-1.14
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• 2020

Background: Dietary protein requirements are dependent on a variety of factors and water temperature is one of the most important abiotic factors affecting protein requirement of fish. This study was, therefore, conducted to investigate effects of water temperature on dietary protein requirement of fry Heteropneustes fossilis which has high demand in most of the Asian markets. Methods: Quadruplicate groups of 30 fish per treatment (2.97 ± 0.65 cm; 5.11 ± 0.34 g) were fed seven isoenergetic diets (17.9 kJ g^-1 gross energy; 14.99 kJ g^-1 digestible energy) containing dietary protein levels ranging from 28 to 52% at two water temperatures (18 and 26 ℃). Experimental diets were fed to apparent satiation as semi-moist cakes thrice daily at 17:00, 12:00, and 17:30 h for 12 weeks. For precise information, various growth parameters, protein deposition, hematological parameters, metabolic enzymes, and stress response were analyzed, and effects of water temperature on dietary protein requirement was recommended on the basis of response from above parameters. Results: Groups held at 26 ℃ attained best growth, feed conversion, and protein deposition at 44% dietary protein indicating that temperature affected dietary protein requirement for optimum growth of H. fossilis fry and protein requirement seems to be satisfied with 44% dietary protein. Interestingly, interactive effects of both dietary protein levels and temperature were not found (P > 0.05). Fish reared at 18 ℃ had comparatively higher values for aspartate and alanine transferases than those reared at 26 ℃ water temperature which exhibited normal physiological value for these enzymes indicating that body metabolism was normal at this temperature. Hematological parameters also followed same pattern. Furthermore, fish reared at 26 ℃ water temperature exhibited more resistant to thermal stress (P < 0.05). The 95% maximum plateau of protein deposition data using second-degree polynomial regression analyses exhibited dietary protein requirement of fry H. fossilis between 40.8 and 41.8% of diet at 26 ℃ water temperature. The recommended range of dietary protein level and protein/digestible energy ratio for fry H. fossilis is 40.8-41.8% and 27.21-27.88 mg protein kJ^-1 digestible energy, respectively. Conclusions: Information developed is of high significance for optimizing growth potential by making better utilization of nutrient at 26 ℃ and, to develop effective management strategies for mass culture of this highly preferred fish species.

• 동아시아식생활학회지
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• 제17권6호
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• pp.827-833
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• 2007

The purpose of the study was to perform research a proximate analyses and sensory evaluations for sulgidduk over a storage period, where the sulgidduk contained added with buchu powder added at 1%, 2%, and 3% concentrations. The general composition of the buchu powder was 34% crude protein, 1.8% crude lipid, and 21.8% crude fiber while the moisture contents of the buchu powder was 2.71%. The moisture contents of the sulgidduk samples over the storage period ranged from 34% to 38%. Color and moisture changes were not significant (p<0.05) during storage, while the values showed significant decreasing trends (p<0.05) with greater additions of buchu powder. In terms of textural characteristics, hardness, cohesiveness, gumminess, and chewiness decreased significantly (p<0.05) with greater concentrations of buchu power, while adhesiveness and springiness showed no significant differences(p<0.05). Based on the sensory evaluations, overall preference was high for the 3% buchu powder sample. This sample received high scores on flavor, color, taste, chewniess, and moisture, suggesting that adding 3% buchu powder would be feasible for making sulgidduk.

• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1777-1781
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• 2003

The lysine requirements of juvenile yellowtail flounder (Pleuronectes ferrugineus) having 19.5 g initial body weight were estimated by feeding six practical-type diets containing graded levels of lysine (1.21 to 2.69% of dry diet). Dietary amino acid profile simulated that of whole body of yellowtail flounder. Most of amino acids in the diets were provided by corn gluten meal, herring meal and gelatin. Protein efficiency ratio (PER) improved significantly until lysine level increased up to 2.1% (4.3% of protein). Same trend was observed in feed:gain ratio (FGR) which maintained constant in fish groups fed diets containing lysine above 2.1%. The highest nitrogen gain (0.34 g/fish) in whole body was found in fish fed 2.1% lysine, though the value was not different from those of fish fed above the level of lysine. Fish fed 2.1% lysine also showed the best nitrogen retention efficiency of 24.6%. The broken-line analysis of protein efficiency ratio and body nitrogen gain against dietary lysine level yielded an estimated lysine requirement of 2.2% (4.5% of protein) and 2.3% (4.7% of protein), respectively.